I think the definitions of commercial interaction between the players and a business can encompass a lot of things. For example:
What if in an alternate universe, RPGS were only played in "dens" or establishments or franchises that controlled the rules and all materials and experiences related to a game. This would be a high level of commercial interaction.
My ideal non-commercial RPG playing alternate universe looks like this:
I think I like my golf analogy where the rules would be standardized by a non-profit body and all the creative business could exist in clubs, tchotchkes, courses to play on, training, clubs etc. Those being campaigns, accessories, adventures, etc. but nothing that futzes with the baseline rules. You can always change the rules in you home game or home organization and if those rules changes become popular, than another group will spring up as a standards-keeper as needed. Rules would always be free to use, the rest would be where the business lies.
Anyway that is my fantasy version of commie D&D. I think we are pretty close to that anyway, where any "pro" game designer/business-person in the industry really doesn't profit that much. I think they could be compensated more if more resources went into organization of the hobby and not competition between a zillion products that are barely different.